Two DX4000: same IP address

This is first time I am experiencing another faunny behavior. I configured two DX4000 with different name, but they all get the same IP address from the DHCP server and this of course cause lot of confusion accessing the units. It might be the case I installed W2008 from the same DX4000 and then moved the drives to another one after having installed the first. Could it be the case that some ethernet MAC addresses are kept within the original W2008 DX4000 configuration and confuse the DHCP server even if there are two different DX4000 with different names?



I would suggest going into your modem/router settings and look for IP Address Reservation settings and assign them separate Static IP Addresses.

My modem/router (TP Link Archer VR1600v) has the setting under Advanced > Network > Lan Settings > Address Reservation

Input the the first DX4000 MAC address and assign it an IP Address. eg.

then input the second DX4000’s MAC address and assign it a different IP Address. eg

click “Save” and problem solved.

Problem is that on the router (Fritzbox 7490) I see only one DX4000… and I am not very keen to set a static address on the DX4000 as I would not like to risk to loose completey its control/access (never tried to check whether the two ethernet ports are really fully independent configuration wise)

You do have your emergency usb nic configured don’t you :slight_smile:)
Long time ago, but I am fairly certain I set static ip

good idea! I will get and configure one before trying to set static IP on the DX4000. Also curious to see whether with another USB NIC the DX4000 will be given the sampe IP address by the DHCP server.

The MAC address for the Intel gigabit ethernet interfaces, is stored in a small serial flash (U3 and U4) on the pcboard. It is possible to change the MAC address by reprogramming the small serial flash. There is one flash for each interface.


Actually the issue had something to do with the MAC address but in the Windows registry. I think the reason why the two units were assigned the same identical IP number was due to the fact that I performed the W2008 install on the same machine and then moved the disks to the second unit. Indeed I found in the registry the MAC address of the ethernet adapters of the original DX4000 which was used for O/S install. I replaced the MAC address with the real one with regedit and magically the DHCP server started assigning to this DX4000 a different IP number. Also forcing static IP address did not solve the problem as the routing from the DHCP had issues.

Now that you mention it, I do remember this issue from a while ago. I have a set of Raid 1 drives for the DX4000 that I use to do quick testing on DX4000 units. This drive set had WS2008 installed on one unit and I got a specific IP address on the front panel. Later when I popped the same drive set into a different DX4000, I was quite surprised to see that the DHCP server had assigned the same IP as the previous DX4000. I never ran both DX4000s at the same time of course, because I only had the one set of drives, but still the DHCP server should not have been handing out the same IP address until the lease expired. Yet it still did. I didn’t make anything of it at the time, but now it makes sense. Windows really ought not be storing MAC addresses in the registry and simply assuming that the network adapters would never change. In this specific case, that they wouldn’t change is a pretty good assumption, but I can imagine cases where you could be swapping network cards around between desktop computers, where it would be a terrible assumption.